1. Field of the Invention
The present invention relates generally to implantable sensors. More specifically, the present invention relates to an implantable glucose sensor with cleaning features.
2. Discussion of the Related Art
Recently, implantable glucose sensors for monitoring glucose concentration level in a patient fluid, such as blood, have been developed. These implantable or in vivo glucose sensors are designed to provide instantaneous reading of patient glucose concentration, where the tip of the glucose sensor is placed within a major blood vessel. Examples of some glucose sensors include U.S. Pat Nos. 4,650,547, 4,671,288, 4,781,798, 4,703,756, and 4,890,620. These implantable glucose sensors can be used in conjunction with an infusion pump system to deliver selected medication, such as insulin, to a patient in a scheduled or preprogrammed manner, including implantable infusion pumps to deliver insulin to the patient in discrete doses over an extended period of time.
However, a potential problem with implantable glucose sensors is that they can have a relatively short life span, often in the order of a few months. This stems from the fact that the implantable glucose sensors are located in a highly volatile environment, such as a large artery, and the human body tends to attack any foreign object placed in the body. Thus, clotting agents in the blood tend to cover and diminish the effectiveness of the sensor with the passage of time. In addition, the sensor can also be covered by proteins, fats, or other substances while the sensor is contact with human blood reducing the life of the sensors.